1. Field
The invention generally relates to wireless communications, and in particular, to power control in a cellular communication system, such as a code division multiple access (CDMA) system.
2. Background
Code Division Multiple Access (CDMA) techniques provide spectrally-efficient solutions to multiplexing data over wireless systems. These systems can include cellular phone networks, wireless telephony systems, personal communications systems (PCS) and the like.
Relatively fast power control loops are typically employed by CDMA systems. Power control is used to prevent disparate signals from interfering with each other and to maintain signal-to-interference plus noise ratios, hereinafter, signal-to-noise ratios (SNR) within desired ranges.
To use spectral bandwidth in an efficient manner, it is desirable to be able to communicate with variable data rates and to adjust a transmitting power with adjustments in the data rate. This uses spectral bandwidth more efficiently and also enhances the battery life of battery-powered stations. However, conventional receivers are not able to distinguish between intentional adjustments to transmitting power due to changes in data rate and changes in received power due to path losses or environmental conditions such as the effects of constructive and destructive multipath interference, also known as Rayleigh fading.